The Roman historian Tacitus’ brief biography of his esteemed father-in-law Cn. Julius Agricola, which he wrote in late 97 / early 98 CE, is acknowledged to be one of our most important literary sources on ancient Britain. It is not, of course, the earliest: Julius Caesar, who invaded Britain two years in a row (55 and 54 BCE) when he was in the process of conquering Gaul, provided accounts of his actions there in his Gallic War (4.20-36 and 5.8-23) and even a brief description of the inhabitants. Thereafter a number of Roman and Greek writers included information on Britain in a variety of historical and geographical works. Tacitus duly notes this abundance of earlier material, but justifies providing yet another account by asserting that it was only in his day that the island was ‘thoroughly conquered’; whereas earlier writers had to compensate for their ignorance with a lot of fancy language, he himself will relay reliable fact (Agricola 10.1).

The basis for Tacitus’ claim to superior knowledge was largely a personal one: his father-in-law Agricola was the man responsible for the island’s having been ‘thoroughly conquered’. Although Tacitus undoubtedly exaggerated in making that claim, it is nevertheless true that Agricola had led the Roman army further north in Britain than it had ever penetrated before and that he had won a major battle in the Scottish Highlands in the year 83 CE. Agricola had in fact already spent a significant part of his career in Britain by the time Tacitus married his daughter in the year 76 CE: he had been a young officer there during the revolt of Boudicca in 60-61 CE, and had served for three years (70-73 CE) as commander of a legion at the time when the Roman governor of Britain was subduing the Brigantes in what is now Yorkshire. Immediately after the marriage of his daughter Agricola returned to Britain, this time as governor himself, and spent the next seven years there solidifying and extending Roman control. It was in the aftermath of his victory in 83 CE that he ordered the first official circumnavigation of Britain by Roman forces (Agricola 38.3-4), which among other things resulted in perhaps the only Roman raid ever on Orkney (Agricola 10.4). Shortly afterwards the emperor Domitian recalled Agricola to Rome, and in the years that followed Tacitus no doubt heard many stories from his father-in-law about his experiences in Britain, before he himself took up a provincial appointment around the year 90 CE. It’s even possible that some of Tacitus’ knowledge of Britain was at first-hand: we know from a fragmentary inscription that he served as a young officer in some unnamed province, and one scholar has made the attractive suggestion that he did so in Britain, in one of the legions over which his father-in-law held supreme command.

Thanks to his connection with Agricola, Tacitus undoubtedly had access to more information about Britain than his predecessors. It’s accordingly something of a letdown to realize how little of it he actually included in his text. The brief overview of Britain that he provides as a preface to his account of Agricola’s governorship (Agricola 10-12) is long on generalizations and short on details; much of it probably does not differ substantially from what could have been found in the work of his predecessors. The same lack of detail characterizes the rest of the work as well: overall, Tacitus mentions the names of only three peoples, three rivers, and three islands, and in no instance does he provide much information. The fact is that, although we may see Agricola as one of our most important literary sources on Roman Britain, that was not Tacitus’ reason for writing it. It’s not that he lacked interest in the peoples and lands on the northern boundaries of the Roman empire: the next work that he composed, immediately after he finished Agricola, was a short monograph devoted entirely to northern Europe and its inhabitants, known today as Germania. In writing Agricola, however, his interests lay elsewhere.

First and foremost, he meant it as a tribute to his late father-in-law. As a result of his provincial appointment, Tacitus and his wife were absent from Rome in 93 CE when Agricola died. Since it would otherwise almost certainly have fallen to him to deliver the funeral speech in his father-in-law’s honour, we may even imagine that Tacitus thought of it as a substitute for the speech that he had not been able to give at the time. It was only because Agricola’s most glorious achievements took place in Britain that Tacitus had anything to say about the place at all, and his interest in it, at least as concerned Agricola’s biography, was almost entirely as a means of highlighting his father-in-law’s accomplishments.

In composing Agricola, however, Tacitus was also pursuing other interests, even if Britain was not one of them. About a year before he began on the work, the emperor Domitian had been assassinated after a fifteen-year reign that saw progressively worsening relations with the senatorial elite. Tacitus’ own relations with Domitian must in fact have been pretty good, at least in public, since his career thrived in that period in a way that it simply could not have if Domitian had been hostile to him. In private, however, as we learn from Agricola itself, Tacitus bitterly resented what he saw as Domitian’s arrogance, secrecy, and poisonous envy, which resulted in a number of oppressive acts and, more importantly, a sense of profound insecurity among the senatorial elite. Although some held up as heroes those members of the senatorial class who made a show of defying the emperor, Tacitus himself was more ambivalent: in his view, their opposition accomplished nothing. For Tacitus, it was his father-in-law Agricola who provided a real role model: through his discretion and devotion to duty he was able to achieve great things even under an emperor who was, in Tacitus’ opinion, hostile to greatness in others. His readers could learn from the life of Agricola how one could be a great man even under a bad emperor (Agricola 42.4).

Yet Tacitus had a concern even more fundamental than that. In the autumn of 93 CE, not long after Tacitus returned from his posting in the provinces, Domitian engaged in one of his most notorious acts of repression. A group of senatorial men and women, who must have been personally known to Tacitus, were prosecuted in a series of treason trials. The charges, it seems, centred on their involvement in composing laudatory biographies of two earlier senators, to whom most of them were in fact related and who had been executed for their outspoken opposition to previous emperors. Tacitus, as I have noted, was ambivalent about presenting these men as heroes, but he was not at all ambivalent about the fact that those who did so were executed or exiled and, perhaps even worse, had very books burnt. This attempt on the part of Domitian to control not only what people did but even what they wrote, said, and thought was for Tacitus the most insidious and most intolerable aspect of imperial power. In the preface to Agricola he laments the extent to which under Domitian people had lost their ability to think independently and express their thoughts openly, as pervasive fear led to systematic self-censorship. Although open defiance of imperial power might have been futile, resistance to the erosion of free thought and free speech was absolutely necessary.

If Agricola disappoints as a source of information about ancient Britain, then, it more than makes up for that by its fierce engagement with an issue that is as important now as it was in Tacitus’ own time. The ability to speak truth to power, the imperative to dismantle the false narratives imposed by those who would control people’s thoughts and speech, remains absolutely central to any sort of political liberty worthy of the name. Tacitus suggests, in the preface to Agricola, that he would next write about the reigns of Domitian’s successors Nerva and Trajan, who had combined things once irreconcilable: liberty and imperial power (Agricola 3.1). In the event, he never did so, but instead kept going further back into the past, as if seeking the roots of the problem that he first grappled with in Agricola. Yet by a curious twist of history, what he attributes to Nerva and Trajan was ultimately fulfilled many centuries later in Britain, the island that for Tacitus was merely the background for his hero’s achievements. It was in Britain, slowly and fitfully and sometimes painfully, that the feat of reconciling monarchy and liberty was most successfully achieved. Yet Tacitus’ short and vivid life of his father-in-law has survived to remind us of the critical and continual importance of freedom of thought and speech.

J.B. Rives is Kenan Eminent Professor and Chair in the Department of Classics, University of North Carolina at Chapel Hill .